Rotatable brush assemblies which can comprise an annular brush member and a brush carrier, can have a brush holder constituted of two end disks spaced apart by a divided spacing bushing or sleeve and axially extending ribs which are spaced from the periphery of the sleeve or bush and which retain the annular brush body between the sleeve and the ribs.
The annular brush can comprise a bendable brush band with outwardly extending bristles and formed with bristle-free zones through which the axial ribs extend.
The resulting brush can eliminate the need for a rubber core or like support and can insure effective positioning and stabilization of the annular brush body so that there will be minimum deformation of the latter resulting from assembly and a cylindrical brush surface, as the working surface will be maintained even though the brush body is composed of bendable material. Such brush assemblies, described, for example, in German Patent 3,741,983, have been found to be effective although capable of improvement.
Another tool in the form of a rotary brush which can be used for the treatment of a workpiece surface can comprise a band of plastic or metal provided with steel wire bristles of equal length. The flat, thin, endless band is placed as a ring around an elastomeric annular body and held under tension thereon by axial deformation of this body between two flanges of a tensioning unit. The axial compression applied between the flanges is transformed into a radial deformation of the support body to press outwardly against the band and tension the latter.
A problem which arises with this system is that the belt itself is not the only elastic or yieldable structure and the yielding contributed by the support may pose problems in certain applications. Such a brush structure is described in German Patent 3 718 932.